This invention relates to an apparatus for pulling fasteners and more particularly to hand tools for pulling upholstery staples and nails.
Fasteners, such as staples and nails, that have been embedded in wood are used in a wide variety of applications. Fore example, fabric is often affixed to the wooden frames of upholstered furniture using upholstery staples. Upholstery staples have elongated points so as to be embedded deep into a wood frame. Upholstery staples are embedded deep into a wooden frame so as to maintain the fabric in place for a long time.
When reupholstering furniture however, it is often very difficult to remove the staples so as to place new fabric on the frame because the staples are embedded very deep into the wood. Generally, the staples are removed by pliers, flat screwdrivers and awls. These tools can make the staple removal process very time-consuming. In fact, it can take nearly one hour for one person to remove the staples from a standard wing chair. In many situations, the staples are left in the frame and a new staple is embedded in the frame at a different location for the new fabric. This latter option is considered to be poor upholstery practice.
Two hand tools have been developed to assist in this process. In U.S. Pat. No. 4,245,817 to Peoples a pneumatic staple puller was proposed. This used two claw members to pierce underneath the crown of the staple and to lift the staple from the wood. U.S. Pat. No. 4,637,538 to Wagner proposed a hand-held tool which is used to drive a wedge underneath the crown of the staple from the side. The Peoples staple puller requires great precision and the ends of the claw members are likely to break after repeated removals. The Wagner staple puller suffers from a disadvantage that it is applied at an angle to the surface in which the staple is embedded. As a result, there will be situations where there will not be room for the main housing of the staple puller because the frame of the furniture will be in the way. As well, the chisel-shaped end portion of the puller must be manually lodged underneath the crown of the staple before the device is activated. This may not be possible when the staple is deeply embedded in the material.
As well, it is also difficult to remove nails embedded in wood. Generally, the claw of a hammer is used to pull a nail from wood. However, if the head of the nail is below the surface of the wood, it is difficult to position the claw underneath the head of the nail.
Accordingly, there is a need for a pneumatically powered fastener puller which is fast, easy to use and may be applied perpendicular to the surface in which the fastener is embedded.
The present invention is accordingly directed to a fastener puller for removing a fastener such as a staple or a nail embedded in a material having a surface.
The subject fastener puller has a handle and connecting means fixedly attached to the handle for connecting a horn to the handle. The horn is mounted on the connecting means and has an elongated stem with an end and a wedge at the end of the stem. The wedge is adapted to fit underneath the head of a fastener. The horn is mounted so that it is moveable relative to the handle from a disengaged horn position to an engaged horn position. An elongated ram is slidably mounted with respect to the handle for longitudinally slidable movement along a slide path from a first ram position through a second ram position to a third ram position. The horn is positioned relative to the ram so that when the ram moves from the first position to the second position, the ram abuts the horn and causes the horn to move from the disengaged position to the engaged position. The ram is positioned so that when the ram moves from the second position to the third position, the ram is in continuous contact with the surface.
The fastener puller may also comprise pneumatic or electrical means for moving the ram along the slide path.
The fastener puller may also have a guide rod fixedly mounted with respect to the handle. The guide rod has a slot adapted to fit about the head of an embedded fastener.
The horn of the fastener puller may be biased to the disengaged position by a biasing member to the disengaged position.
In another aspect of the invention, the staple puller may have an adjusting member for adjusting the position of the horn with respect to the guide rod.
In an alternative embodiment to the invention, the staple puller may have a ram handle with an elongated ram fixedly mounted on the ram handle. A pull member is slidably mounted with respect to the ram handle and a horn is pivotally mounted to the pull member. The horn has an elongated stem and a wedge at the end of the stem. The wedge of the horn is adapted to fit underneath the crown of the staple. The horn is pivotable from a first horn angle relative to the ram to a second horn angle. The horn is positioned so that when the ram is pushed towards the surface, the ram abuts the horn and moves the horn from the first horn angle to the second horn angle.